Sheet feeding mechanism



July 26, 1960 SPIRO ETAL 2,946,589

SHEET FEEDING MECHANISM Filed March 19, 1958 4 Sheets-Sheet 1 IN VENTORS Maze/4 Y JP/Ieo 620262- Maven,

July 26, 1960 Filed March 19, 1958 M. sPlRo. ETAL 2,946,589

SHEET FEEDING MECHANISM 4 Sheets-Sheet 2 T 3 INVENTORS M224? J'p/ea BY v 770IVEY July 26, 1960 SPIRQ ETAL SHEET FEEDING MECHANISM 4 Sheets-Sh eet 5 Filed March 19, 1958 INVENTORS All/224v JP/EO 6:024: Ai /Maw ZIP/V5) 4 Sheets-Sheet 4 July 26, 1960 s o ETAL SHEET FEEDING MECHANISM Filed March 19, 1958 T. P E 0 WYM r N A 4 26 WWW United States Patent 5,946,589 SHEET FEEDING MECHANISM Murray Spiro, 163-28 17th Ave, Whitestone, N.Y., and George Neimeth, 67-41 161st St., Flushing, NY.

Filed Mar. 19, 1958, Ser. No. 722,424

14 Claims. (Cl. 27126) This invention relates generally to sheet feeding mechanisms and particularly to such mechanisms as are intended for feeding sheets to a printing (or other) machine in the course of the method known as stream feeding wherein the sheets travel from the supply position to the aforesaid machine in partly lapped formation. However, the invention may also be employed for feeding sheets from a stack of sheets regardless of the method of their accumulation in said stacks.

It is an object of the present invention to accomplish a rapid engagement of the top sheet of a stack of sheets, whereby said sheet may be separated and fed to such a machine.

A further object of the invention is to provide a device which may accomplish the aforesaid separation and feeding in continuous stream feeding as well as in pile stream feeding operations.

A still further object of the present invention is to achieve smoothness of operation at a high rate of speed in the course of such operations.

Other and more specific objects of the present invention will be apparent from the following description as read in connection wit-h the accompanying drawings.

In the drawings:

Fig. l is a perspective view of one embodiment of the invention;

Fig. 2 is a perspective view of one of the units employed in the said embodiment of the invention;

Fig. 3 is a diagrammatic elevational view depicting one operative position of a portion of the unit depicted in Fig. 2;

Fig. 4 is a diagrammatic elevational view of another operative position of the portion of the unit illustrated in Fig. 3;

Fig. 5 is a partially cutaway top View of the unit depicted in Fig. 2;

Fig. 6 is an enlarged cross-sectional view taken about the line 6-6 in Fig. 5;

Fig. 7 is a cross-sectional view taken about the line 77 in Fig. 6;

Fig. 8 is an enlarged cross-sectional View taken about the line 8-8 in Fig. 5;

Fig. 9 is a cross-sectional view taken about the line 99 in Fig. 8; i

Fig. 10 is an enlarged cross-sectional view taken about the line 1010 in Fig. 8;

Fig. 11 is an enlarged cross-sectional view taken about the line 11-11 of Fig. 6;

Fig. 12 is a cross-sectional View taken about the line 1212 of Fig. 6;

Fig. 13 is an enlarged cross-sectional view taken about the line 1313 in Fig. 5.

Similar reference numerals indicate corresponding parts throughout the several views.

As shown in the accompanying drawings, one form of the invention may be employed as a device for feeding sheets from a stack thereof to the feed rolls of a 2 sheet handling machine such as a printing machine; Thus, in Fig. 1 there is depicted a stack of sheets, generally designated by the numeral 20*, and the said form of the invention in operative position with respect to the said stack. This stack may be composed of sheets of paper which have been collected by pile stream feeding, coritinuous stream feeding or by any process which result in accumulation of a stack of such sheets. 7 V V The form of the invention illustrated'in Fig. '1 iricludes a pair of units, generally designated by the nu;- merals 21, 22 and laterally disposed with respect to each other in the vicinity of the upper portion of'a stack of sheets. Each of these units operates in substantially the same manner. I

Unit 21 is depicted in Fig. 2. As' shown in this figure, this unit comprises a sheet lifting means projecting from a housing 2.3, a pair of sheet forwarding means projecting from housings 24, 2S and gear box 26'. The said housings and gear box are supported by suitable mounting shafts 2'7 and 28; and a cam shaft 29 also extends into said housings and gear box. A feed roll 30 is mounted upon a shaft 31 projecting from the said gear box. The said sheet lifting means. is generally designatedby the numeral 32; and the said sheet forwarding meansare each generally designated by the numeral 33.

Spring clips 34, 35, 36 and air blast separators 37, 38, 39, 40 of conventional design are suitably mounted in positions illustrated in Fig. 2.

Figs. 3 and 4 illustrate the raising of sheets by, the aforesaid sheet lifting means. Thus, in Fig. 3, there is shown one end of a stack of sheets in the vicinity of feed roll 3% which coacts with an upper rotatable feed roll 41. Feed roll 41 is of conventional design and is sup ported by a suitably mounted shaft 42. It is tobe noted that the end of the stack' of sheets shown in'Fig. 3 is denominated the frontward end and that, as hereinafter more fully pointed out, the lifting and forwarding of the sheets from the stack occurs by operations performed in the vicinity of this end of the sheets. This is an important feature of the invention in that these operations permit the sheets to be pulled into engagement with the feed rolls 30, 41 and hence allow great sheet feeding speed and smoothness of performance.

Sheet lifting means 32 includes a tube 43 communicating with a suction cup 44. Said suction cup maybe inclined as shown in Fig. 3, where it is depicted inits initial position slightly above the stack. As shownin Fig. 6, the position of suction cup 44 above the stack is determined by an adjustable stop assemblymounted upon tube 43 and comprising a horizontal flange 43a integral with said tube, nut and lock washer assemblies- 43b in contact with said flange and threadedly engaged with a vertical stud 43c, which may be rotatably'adjusted; so as to project toany desired distance below rthe' level of suction cup 44. There a vacuum exerted-by way of said suction cup will be sufiicient to lift the top sheet 45 of said stack into engagement with the suction cup, which is then lifted to the position shown in'FigJ4. The aforesaid initial positionof the suction cup is one wherein it is slightly above and out of contact with the stack until the top sheet is drawn into engagement with' the said cup, thereby preventingthe communicatio-n'bf suction through openings due to any porous condition of the top sheet to the sheet beneath it and hence preventing the lifting of more than one sheet at a time. To facilitate the same result, the aforesaid spring clips 34, 35 and 36- maintain a yielding pressure upon'the stack,thereby promoting the lifting of only the top' sheet of saidstack by the aforesaid suction cup. 7 V H Fig. 3 also shows a sheet 46 which is being. advanced in the direction of the arrow therein indicated by 'feed rolls 30, 41 after having been forwarded thereto by means hereinafter more fully described. As shown in Fig. 4, when the top sheet 45 is raised by suction cup 44, a. stream of air emerges from .air blast separators 39 and 40 (shown in Fig. 2) and blows sheet 46 away from the tube 43, thereby preventing marring of the underside of said sheet 46. Air blast separators 37 and 38 are suitably adjusted to fluff the upper sheets of the stack just prior to and during the aforesaid lifting operation.

As hereinafter set forth, sheet 45 will be disposed in the position of sheet 46, shown in Figs. 3 and 4, as soon as said sheet 46 has been advanced by the feed rolls 30, 41 so as to avoid interference with sheet 45, by which time sheet lifting means 32 will also have been retracted to itsoriginal position depicted in Fig. 3. Thereafter, the above described lifting cycle of sheet lifting means 32 may be repeated as often as desired.

The mechanism for accomplishing this lifting cycle may be understood more fully by reference to Figs. 5, 6 and 7. Thus, Fig. 5 illustrates, among other things a top view of the housing 23 for the sheet lifting means 32, said housing 23 being shown with its upper portion cutaway. As shown in Figs. 6 and 7, the sheet lifting means comprises the aforesaid tube 43 communicating with suction cup 44. Tube 43 is integral with a.solid shank generally designated by the numeral 47 and slidably received in sleeve 48, which is pivotally mounted on shaft 49, the latter being journalled in housing 23. The external portion of sleeve 48 has a rectangular conformation, as shown in Fig. 7. The vertical shank 47 is provided with a laterally projecting pin 50, which is engaged with an elongated slot 51 provided in one side of sleeve 48.

As shown in Fig. 11, the said pin 50 is provided with a reduced cylindrical portion 50a, retained within shank 47, as can be seen in this figure, as well as in Fig. 6; the said pin is also received within an arcuate slot 52 of a rocker arm, generally designated by the numeral 53.

This rocker arm 53 is pivotally mounted upon a shaft 54. As can be seen in Fig. 12, this shaft is journalled in a boss 55 integral with the housing 23, said shaft also being journalled in a flange 56 integral with a web 57. The said web 57 projects transversely within the interior of the housing 23 and is integral therewith.

As shown in Fig. 6, the said rocker arm 53 is also provided with an inclined finger 58 which is integral with said rocker arm. A roller 59 is rotatably mounted upon a shaft 60 retained in said finger by a nut and lock Washer assembly, generally designated by the numeral 61a, said nut being threadedly engaged with the shaft 60.

The roller 59 is maintained in contact with a cam 61 secured to camshaft 29. With this arrangement, it will be seen that upon rotation of the cam 61 as, for example, in the counterclockwise direction indicated by the arrow shown in Fig. 6 the rocker arm 53, acting upon the pin 50, will reciprocate shank 47 radially of the shaft 49. The said shank 47 is also provided with an electrical contact arm 62 contactable with an electrical switch 63 mounted upon the sleeve 48. When arm 62 contacts switch 63, a lifting device, such as an electrically operated hoist (not shown), will be activated to lift the stack of sheets so that its top sheet will be at the level shown in Fig. 8.

The shank 47 is also provided with a boss 64, which is threadedly engaged with the nipple 65 of a pneumatic suction tube, said nipple communicating with the interior of tube 43, thereby permitting suction to be exerted through suction cup 44.

As pointed out hereinabove, the sleeve 48 is pivotally mounted upon shaft 49. This sleeve is also provided with a flange 66 mounted upon said sleeve. The said flange is provided with an horizontal pin 67 received within an arcuate slot 68 included in an horizontal arm,

generally designated by the numeral 69. The said arm has an intermediate portion 70 which has a rectangular cross-sectional conformation and which is slidably received within web 57, as can be best seen in Figs. 6, 7 and 12. A roller 71 is rotatably mounted upon a shaft 72 retained in said arm by a nut and lock washer assembly, generally designated by the numeral 73, said nut being threadedly engaged with the shaft 72.

The roller 71 is in contact with a cam 74 secured to camshaft 29. With this arrangement, upon counterclockwise rotation of cam 74, the horizontal arm 69, acting upon sleeve 48 will pivot said sleeve about shaft 49.

An extension spring 75 is also anchored to sleeve 48 and web 57, thereby exerting a constant tension upon said sleeve, which acting upon horizontal arm 69 and roller 71, maintains the said roller in contact with cam 74.

Of course, earns 61 and 74 are provided with contours suitable to accomplishing the aforesaid reciprocating and pivoting motions.

It is therefore clear that these cams may be secured upon shaft 29 at a suitable rotational displacement with respect to each other so that the shank 47 may be reciprocated within sleeve 48 and at the same time pivoted by said sleeve, all in accordance with any predetermined cycle. Thus, in the present invention suction cup 44 moves through a cycle wherein it engages the top sheet of a stack 20, as hereinbefore described, and lifts said sheet to a predetermined position, where it is engaged by sheet forwarding means as hereinafter described. Then the suction cup isreleased from the Sheet and rocked in a clockwise direction by the aforesaid pivoting motion to a position where said suction cup is in front of said sheet. The suction cup is then lowered by the aforesaid reciprocating motion without interfering with said sheet, and is pivoted to its initial position where it may engage thelnext top sheet of the stack and repeat the aforesaid cyc e.

The mechanism of the sheet forwarding means may be understood more fully by reference to Figs. 5, 8 and 9. Thus, Fig. 5 illustrates, among other things, a top view of the housing 24 for the sheet forwarding means 33, said housing being shown with its upper portion cut away. As shown in Figs. 8 and 9, the sheet forwarding means 33 comprises a suction cup 76 mounted upon a bar 77, slidably retained within a sleeve 78. The external portion of this sleeve has a rectangular conformation, as can be seen in Fig. 10, and said sleeve is pivoted on shaft 79 journalled in housing 24. An inclined finger, generally designated by the numeral 80, is integral with said sleeve and is provided with a transverse shaft 81 upon which a roller 82 is rotatably secured.

This roller 82 is maintained in contact with a cam 83 secured to camshaft 29. With this arrangement it will be seen that upon rotation of the cam 83, as for example, in the counterclockwise direction indicated by the arrow shown in Fig. 8, the inclined finger 80, being integral with the sleeve 78, will rock said sleeve about shaft 79. Since bar 77 is contained in the sleeve 78, the said bar will also rock about said shaft 79, thereby displacing the suction cup in a vertical plane including its position, as shown in solid lines in Fig. 8, and its position as designated in the said figure by the numeral 76a.

The bar 77 is also provided with a laterally projecting pin 84 which is engaged with an elongated slot 85 provided in one side of sleeve 78. As shown in Fig. 10, the said pin 84 is provided with a reduced cylindrical portion 84a retained within the bar 77. As can be seen in this figure, as well as in Figs. 8 and 9, the said pin 84 is also received within an arcuate slot 86 of a rocker arm, generally designated by the numeral 87. This rocker arm is pivotally mounted upon a shaft 88 journalled in housing 24.

An inclined finger 89 is integral with the rocker arm 5 87 and is provided withatransverse shaft '90'upon-which a roller 91 is rotatably mounted.

This roller 91 is maintained in-contact with a :cam 92 secured to camshaft 29. With this arrangement it will be seen that upon rotation of the cam 92, as for example, in the counterclockwise direction indicated by the .arrow shown in Fig. 8, the inclined finger 89, being integral with rocker arm 87, will rock said arm about shaft 88, thereby acting upon pin 84 so as to reciprocate bar 77. By virtue of this motion suction cup 76 will move in a vertical plane including its position as shown in solid lines in Fig. 8 and its position as designated insaid figure by the numeral 76b.

Cams 83 and 92 are provided with contours suitable to accomplishing the aforesaid reciprocating and pivoting motions of the sheet forwarding means.

These cams may be secured upon shaft 29 at a. suitable rotational displacement with respect to each other so that the bar 77 may be reciprocated within sleeve 78 and at the same time pivoted about shaft 79, all in accordance with any predetermined cycle, and so as to move suction cup 76 to any predetermined position within that cycle, as for example, the position indicated by thenumeral 760 in Fig. 8.

Therefore, when the suction cup 44 of the sheet lifting means has raised the top sheet of the stack to the position occupied by sheet 45 in Fig. 4, the suction cup 76 may assume the position indicated by the numeral 760 of Fig. 8, after having been moved through previous positions such as are designated in said Fig. 8 by the numerals '76 and 75b. In the position indicated by the numeral 760, the suction cup will engage the underside of sheet 45, it being understood that suction is created'by a suitably decreased pressure communicated to said suction cup by way of an aperture 93' in said bar 77, said aperture being in communication with the said suction cup and also being connected to a suitable vacuum.

When the underside of sheet 45 has been engaged by the suction cup in the position indicated by the numeral 760, the sheet lifting means may be disengaged from the upper side of said sheet and retracted to its original position shown in Fig. 3. In the meanwhile, suction cup 76 may move with sheet 45, to the position indicated by the numeral 76a in Fig. 8. In this position, the sheet 45 will be engaged and advanced by feed rolls and 41; and once it has been so engaged, the suction cup may be retracted to a position such as that indicated by the numeral 76 in Fig. 8, whereafter the same cycle may be repeated.

t is to be noted that the position of the suction cup indicated by the numeral 760 is slightly inclined so that the top of said suction cup is in a plane substantially corresponding with that occupied by the bottom of suction cup 54 at the time when the underside of the top sheet is engaged by the suction cup indicated by the numeral 76c.

It is to be understood that camshaft 29 extends through housings 23, 24 and 25, as well as through gearbox 26; and that cams 61., 74, 83 and 92 are rotationally displaced with respect to each other and secured to said camshaft 29 so as to coordinate the aforesaid sheet lifting and sheet forwarding operations.

Mounting bars 27 and 28, and camshaft .29are also common to unit 22, as Well asto the various components of unit, as foresaid. Hence, it is clear that units 21 and 22 will act in unison in lifting and forwarding sheets, each of said units operating in the manner hereinabove set forth.

It is also to be understood that housing 25 is substantially identical with housing 24; and that the mechanism contained in housing 25 is substantially identical with that contained in housing 24.

As can be seen in Fig. 2, apertures 94, 95 and 96 are provided in housings 23, 24 and 25, respectively, thereby accommodating the sheet lifting and sheet forwarding mechanismscontained therein. i

similar gear box constituting a portion of unit 22, and

containing a substantially identical drive gear and gear .trainasxhat included withingear box 26, it is clear that these gears will rotate in unison. vMoreover, since, as pointed out above feed roll 30 is mounted upon shaft 3-1 and since there is a substantially identical feed roll in unit 22, these feed rolls will also rotatein unison, thereby permitting a uniform engagement of the sheets fed to said rolls.

"Cam shaft 29'may be provided with suitable driving means, such as a suitable gear or pulley drive, said driving means being mounted at any convenient location on cam shaft 29, such as the portion thereof in the vicinity of numeral29--in Fig. 1. V

The embodiment of the invention illustrated and described hereinabove has been selected for the purpose of clearly setting forth the principles involved. It will be apparent, however, that the present invention is susceptible to being modified in respect to details of construction, combination and'arrangement of parts which may be resorted to without departure from the spirit and scope of the invention as claimed.

We .claim:

'1. In a device for stream-feeding sheets from a stack, the combination comprising sheet-lifting means engaging the upper frontwardportion-of the top'sheet of the stack, whereby the saidttop-sheetmay be displaced in a vertical path from the stack, and sheet forwarding means engagingthe lower frontward portion of the top sheet when it is displaced by the said'sheet lifting means, the said sheet forwarding means initially engaging the top sheet when it is entirely disposed within said vertical path.

.2. :Iniadevice forstreamfedingsheets from a stack, the;combination comprising'sheet lifting means engaging .the upperfrontward portion of the top sheetof the stack, said sheet lifting means including at least one suction cup contactable with :said upper frontward portion whereby .thesaidtop sheet may be displaced ina vertical path from the stack, and'sheet forwarding means engaging the lower frontward 'portionof the top sheet when it is displaced byzthe said sheet lifting means, the said sheet forwarding meansincluding'at least one suction cup contactable with said lower frontward portion, the said sheet forwarding means initially engaging the top sheet when it is entirely disposed within said vertical path.

3. In adevice for stream-feeding sheets from astack, the combination comprisingsheet liftingmeans engaging the upper frontward portion of the top sheet of the stack, said sheet lifting means including at least one suction cup contactable with said upper frontward portion, means for vertically reciprocating said suction cup, whereby the said top sheet may be displaced in a vertical path from the stack, and sheet forwarding means engaging the lower frontward portion of the top sheet when it is displaced by the said sheet lifting means, the said sheet forwarding means including at least one suction cup contactable with said lower frontward portion and means for.reciproeating said suction cup forwardly of said stack, the said .sheet forwarding means initially engaging the top sheet when it is entirely disposed within said vertical path.

4. .A device according to claim 1, the said sheet lift- )ing meansand sheetlforwardingmieans engaging the .top sheet consecutively.

i5. A .deviceaccording toclaini :1, said sheet lifting 7 means being disengaged from the said top sheet after it is engaged by the said sheet forwarding means.

6. In combination with the feed rolls of a sheet handling machine, a device for feeding sheets from a stack comprising in combination sheet lifting means engaging the upper frontward portion of the top sheet of the stack, whereby the said top sheet may be displaced in a vertical path from the stack, and sheet forwarding means engaging the lower frontward portion of the top sheet when it is displaced by the said sheet lifting means, whereby the said sheet is moved into the vicinity of the said feed rolls, the said sheet forwarding means initially engaging the top sheet when it is entirely disposed within said vertical path.

7. In a device for stream-feeding sheets from the top of a stack, the combination comprising a first set of suction cups operable at separated points near the front edge of the stack on the upper surface of each sheet in turn to lift it, and a second set of suction cups operable while the first set of suction cups maintains its grip on the sheet to contact the lower surface of the sheet at separated points near the front edge thereof and to take each sheet in turn from the said first set of suction cups and pull it forwardly of the said stack.

8. In a device for stream-feeding sheets from the top of a stack, the combination comprising a first set of suction cups operable at separated points near the front edge of the stack on the upper surface of each sheet in turn to lift it, and a second set of suction cups operable while the first set of suction cups maintains its grip on the sheet to contact the lower surface of the sheet at separated points near the front edge thereof and to take each sheet in turn from the said first set of suction cups and pull it forwardly of the said stack, the said first set of suction cups being movable forwardly of said sheet after said contact with the lower surface thereof by said second set of suction cups, and means to lower the said first set of suction cups below the said sheet after said first set of suction cups is moved forwardly of said stack.

9. In a device for stream-feeding sheets from the top of a stack, the combination comprising a first set of camoperated suction cups operable at separated points near the front edge of the stack on the upper surface of each sheet in turn to lift it, a second set of cam-operated suction cups operable while the first set of suction cups maintains its grip on the sheet to contact the lower surface of the sheet at separated points near the front edge thereof and to take each sheet in turn from the said first set of suction cups and pull it forwardly of the said stack, means for pivoting the said first set of suction cups forwardly of said sheet after said contact with the lower surface of the sheet by the second set of suction cups, and means to lower the said first set of suction cups below the said sheet after said first set of suction cups are pivoted forwardly thereof, each of said means being mounted forwardly of said stack.

10. In a device for stream-feeding sheets from the top of a stack, the combination comprising a first set of suction cups operable at separated points near the front edge of the stack on the upper surface of each sheet in turn to lift it, the said first set of suction cups being associated with reciprocable tubes slidably received in rockable sleeves, the said rockable sleeves being pivotably mounted forwardly of said stack, the said sleeves being operable in association with a set of cam-operated arms, a second set of suction cups operable while the first set of suction cups maintains its grip on the sheet to contact the lower surface of the sheet at separated points near the front edge thereof and to take each sheet in turn from the said first set of suction cups and pull it forwardly of the said stack, the said rockable sleevm pivoting the said first set of suction cups forwardly of said sheet after said contact with the lower surface thereof by said second set of suction cups, the said reciprocable tubes lowering the said first setof suction cups below the s,

8 said sheet after said first set of suction cups are pivoted forwardly thereof.

11. In a device for stream-feeding sheets from the top of a stack, the combination comprising a first set of suction cups operable at separated points near the front edge of the stack on the upper surface of each sheet in turn to lift it, the said first set of suction cups being associated with reciprocable tubes slidably received in rockable sleeves, the said rockable sleeves being pivotably mounted forwardly of said stack, the said sleeves being operable in association with a set of cam-operated arms, a second set of suction cups operable while the first set of suction cups maintains its grip on the sheet to contact the lower surface of the sheet at separated points near the front edge thereof and to take each sheet in turn from the said first set of suction cups and pull it forwardly of the said stack, the said rockable sleeves pivoting the said first set of suction cups forwardly of said sheet after said contact with the lower surface thereof by said second set of suction cups, the said reciprocable tubes lowering the said first set of suction cups below the said sheet after said first set of suction cups are pivoted forwardly thereof, the said second set of suction cups being associated with retractable bars slidably received in pivotable sleeves, the said retractable bars being in association with a second set of cam-operated arms, the said pivotable sleeves being mounted forwardly of said stack and associated with a third set of cam-operated arms.

12. In a device for stream-feeding sheets from the top of a stack, the combination comprising a first set of suction cups operable at separated points near the front edge of the stack on the upper surface of each sheet in turn to lift it, the said first set of suction cups being associated with reciprocable tubes slidably received in rockable sleeves, the said rockable sleeves being pivotably mounted on a set of horizontal members disposed forwardly of said stack, the said sleeves being rockable in association with a first set of arms, the said tubes being reciprocable in association with a second set of arms, cam means driving said first and second set of arms, driving means for rotating said cam means, a second set of suction cups operable while the first set of suction cups maintains its grip on the sheet to contact the lower surface of the sheet at separated points near the front edge thereof and to take each sheet in turn from the said first set of suction cups and pull it forwardly of the said stack, the said first and second sets of arms rocking the said sleeves forwardly of said sheet after said contact with the lower surface thereof by said second set of suction cups, whereby the said first set of suction cups are pivoted forwardly of said sheet, the said reciprocable tubes cooperating with said second set of arms to lower the said first set of suction cups with respect to the said sheet after they are pivoted forwardly thereof, the said second set of suction cups being associated with retractable bars slidably received in pivotable sleeves mounted on a second set of horizontal members disposed forwardly of said stack, the said retractable bars being reciprocable in association with a third set of arms, the said sleeves being pivoted in association with a fourth set of arms, cam means driving said third and fourth sets of arms, and driving means for rotating said last-mentioned cam means.

13. In a device for stream-feeding sheets from a stack, the combination comprising sheet lifting means engaging the upper frontward portion of the top sheet of the stack, whereby the said top sheet may be displaced in a vertical path from the stack, and sheet forwarding means engaging the lower frontward portion of the top sheet when it is displaced by the said sheet lifting means, the said sheet forwarding means initially engaging the top sheet when it is entirely disposed within said vertical path, the said sheet liftng means disengaging the upper frontward por' tion of the top sheet of the stack and engaging the upper frontward portion of the sheet below said top sheet subamuse Stantially at the time of the said engagement of the lower frontward portion of the top sheet by the said sheet forwarding means.

1.4. In a device for stream-feeding sheets from a stack, the combination comprising sheet lifting means engaging the upper frontward portion of the top sheet of the stack, said sheet lifting means including at least one suction cup contactable with said upper frontward portion whereby the said top sheet may be displaced in a vertical path from the stack, and sheet forwarding means engaging the lower frontward portion of the top sheet when it is displaced by the said sheet lifting means, the said sheet forwarding means including at least one suction cup contactable with said lower frontward portion, the said sheet forwarding means initially engaging the top sheet when it is entirely disposed within said vertical path, the said suction cup contactable with the upper frontward portion of 10 the top sheet of the stack disengaging therefrom and engaging the upper frontward portion of the sheet below said top sheet substantially at the time of the engagement of the lower frontward portion of the top sheet by the suction cup contactable with said lower frontward portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,108,702 Backhouse i Feb. 15, 1938 2,183,077 Kast Dec. 12, 1939 2,233,935 Backhouse Mar. 4, 1941 2,236,363 Backhouse Mar. 25, 1941 2,389,480 Baker Nov. 20, 1945 2,454,762 Belluche Nov. 30, 1948 2,591,116 Backhouse Apr. 1, 1952 2,848,227 Gulick Aug. 19, 1958 2,869,867 Backhouse Jan. 20, 1959 

